Completely new - potentially using CNC to produce test samples

(Chris Klein) #1

Hi All -

We produce specialty epoxy compounds used as adhesives, potting compounds and coatings for specific OEM applications. We presently mold parts for mechanical, thermal and electrical testing , and while that works for more liquid systems, the thicker, more highly-filled systems can be difficult to prepare Obviously, sample prep is critical for accurate results in specific thermal conductivity and mechanical testing and we’ve reached our limit in the molding/cutting/sanding process of producing parts for specific tests. That has lead us to recently discussed getting a small CNC machine for the lab to look at perhaps machining the parts to replace the molding/cutting/sanding process.

One caveat - our materials may be highly filled with a variety of abrasive materials depending upon the properties required, so, if we go the CNC route, we’d need the right cutting and milling substrates.

In general, we would not be making ‘pretty’ parts, i.e., not complex at all. For example, one ASTM test for three point bend requires a part that is 1"x4"x0.225". Another would be a ‘dogbone’ sample per ASTM D638 Type 2. The key for us would be to produce parts accurately and reproducibly,

Is there someone we can/should talk to about our questions/concerns? The Nomad 833 struck us as a good starting point, but at the end of the day, we’re really good chemists, good material scientists, so-so mechanical engineers and really bad graphic designers…


(William Adams) #2

Thanks for considering us! Please feel free to e-mail if you have any specific questions.

That said, we’ve tried very hard to make the Nomad “the CNC for the rest of us” and we have a standing offer for anyone who is having trouble fashioning a part in MeshCAM or Carbide Create to send it in and we’ll work up a step-by-step tutorial on how to accomplish it.

The nice thing is, once one has the files for making a given part done, re-running the file produces essentially identical results.

(Adam X) #3

There are many semi-kit and ready-to-run small CNC table solutions out there. Based on your sizes above, most any of them should be able to get the work done. Sourcing good cutters is not all that difficult, just potentially expensive.

Carbide3D excels in supporting their machines, which is the reason I purchased from them and continue to champion their equipment (no, I don’t work here). If you have a problem and work WITH support, they will get it solved.
The Nomad (and Shapeoko3) being based on a GRBL motion controller also keeps your very ‘Free’ in terms of your workflow - you are not bound to the software supplied by Carbide3D, if you did not want to use it.

If all you need to make are basic cuts on 2D shapes, you should have no issues with a Nomad, CarbideCreate and CarbideMotion.


The Nomad is a very capable machine within, and is quite accurate for the price. There are people (including me) that use it for a variety of plastics, composites, and metals with excellent results. The moderate size work envelope in a full enclosure is a very nice thing. For high throughput or materials tougher to machine than aluminum, you might find the spindle power an issue, but to get higher throughput, you would need to either sacrifice accuracy or money.

Any of the smaller machines will also likely need you to set up your own dust/chip extraction methods. It isn’t that difficult, and there are a number of examples throughout this forum, but when working with abrasive or friable materials, it is needed to avoid damage to the machine or to the operator. You have roughly the same considerations as when sanding as far as dust control. To get the dust/chip control built into the machine, you are probably looking at an order of magnitude or more increase in price and complexity, and a significantly larger footprint.

(Kris Van) #5

+1 on the support, above and beyond what I ever expected. Had an error code I had never seen yesterday during a run, posted the question on the forum, and within 15 minutes had responses from Will and another highly skilled forum member. Problem solved.